Improvement in screw-cutting dies



G. R, STETSON. Screw-Cutting Dies.

No. 203,956. Patented May 2 1,1s7s..

' WITNESSES: f j INVENTOR:

. ATTORNEYS.

UNITED ES PATENT OFFICE.

GEORGE E. STETSON, OF NEW BEDFORD, MASSACHUSETTS, ASSIGNOR TO HIMSELF AND MORSE TWIST DRILL AND MACHINE COMPANY, OF THE.

SAME PLACE.

lMPR OVEME NT IN SCREW-CUTTING DIES.

Specification forming part of Letters Patent No- 203,956, dated May 21, 1878; application filed April 26, 1878.

To all whom it may concern:

Be it known that I, GEORGE E. STE'rsoN,

of New Bedford, in the county of Bristol and sponding parts.

My invention relates to. dies for cutting screw-threads and it consists in a holder formed of a solid piece of metal, having a centralaperture for receivin gthe article to be threaded,

. and slots for receiving the chasers or threadcutters, and having recesses for containing fastening-plates, which engage grooves formed in the sides of the chasers.

In the drawing, A is a block or holder, of iron or steel, having a central aperture, b, for receiving the article to be threaded, and having four radial slots, 0, to which are fitted the dies or chasers cl.

At diametrically-opposite sides of the central aperture there are two slots, 6, which are parallel with the sides of the block or holder, and extend from one slot 0 to another.

In the slot 6 is placed a thin piece of metal,

' j, which conforms to the shape of the slot, and

has its ends out at proper angles to each other. In one side of each chaser there is a groove, 2', and the grooves in each pair of chasers face the intervening piece f, and receive the ends of the said piece when the chasers are fastened in the slotsc.

Ascrew, 9, extends fromone or more of the corners of the die or block to the slot 0, and bears against the plain end of the chaser which it is designed to adjust.

In opposite sides of the block, and opposite the middle of the slots 6, there are screws h, which bear against the pieces f and force them against the chasers, clamping them securely in their slots 0. The chasers may be easily re moved by retracting the-screws h and forcing back the pieces f.

My improved die is intended for threading pipe-bolts, &c., and may be readily adjusted, repaired, or sharpened.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- The chasers d, having side slots, the fastening-pieces f, and the slotted block or body A, having the adjusting and binding screws h, in

combination, substantially as shown and described.

GEORGE RIPLEY STETSON. Witnesses:

GIDEON ALLEN, J r.,

DANL. W. CORY. 

